title: Development and primary application of a fluorescent liquid bead array for the simultaneous identification of multiple genetically modified maize.
abstract: An integration event-specific fluorescent liquid bead array was developed for the simultaneous identification of 10 genetically modified (GM) maize, including Bt176, Bt11, MON810, NK603, GA21, MON88017, MON89034, MIR604, T25 and MIR162, as well as one non-GM maize. The system comprised 11 specific oligonucleotide probes labeled with an amino group and coupled to fluorescence-encoded microspheres. To enable fluorescence detection, 11 pairs of primers labeled with biotin at the 5' ends were used. The hybridization signal of biotinylated PCR product to the probe-coupled microspheres was then detected. The limit of detection of this assay was 0.1% for GM maize, which is lower than the current labeling threshold levels enforced in the EU (0.9%). The results of the positive and negative controls were consistent with their expected situation, which showed that the method was highly specific. We detected GM maize in 20 of the 1370 commercial food samples tested, which were labeled as containing maize. The overall sensitivity, specificity, rapidity and high throughput capacity of this liquid chip system suggest that it could provide a significant improvement over current methods, and potentially offer an improved platform for further research into the detection of other GM plants.
authors.affiliation: Chinese Academy of Inspection and Quarantine, Room 614, Building 241, HUIXINLI, Huixinxi Street, Chaoyang District, Beijing 100029, China. hanxueq@yahoo.com.cn
authors.forename: Xueqing
authors.initials: X
authors.lastname: Han
authors.forename: Huiyu
authors.initials: H
authors.lastname: Wang
authors.forename: Hongjun
authors.initials: H
authors.lastname: Chen
authors.forename: Lin
authors.initials: L
authors.lastname: Mei
authors.forename: Shaoqiang
authors.initials: S
authors.lastname: Wu
authors.forename: Guangle
authors.initials: G
authors.lastname: Jia
authors.forename: Tao
authors.initials: T
authors.lastname: Cheng
authors.forename: Shuifang
authors.initials: S
authors.lastname: Zhu
authors.forename: Xiangmei
authors.initials: X
authors.lastname: Lin
mesh_terms: D018744:DNA, Plant / Q000032:analysis*; D005453:Fluorescence; D005504:Food Analysis / Q000379:methods; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods*; D030821:Plants, Genetically Modified / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D003313:Zea mays / Q000235:genetics*
chemical_list: D018744:DNA, Plant
keywords: Detection; Event-specific; GM maize; Suspension arrays